An anti-war Republican. The speaker of the House. And an “American Idol” runner-up. All three are running in House primaries Tuesday, when voters in three states — North Carolina, Indiana and Ohio — head to the polls.

Several intriguing races are in North Carolina: GOP Rep. Walter Jones, who opposed the Iraq War, is trying to beat back Taylor Griffin, a former George W. Bush aide; in the race for the vacant 7th District, the GOP establishment has lined up against Woody White, an immigration hard-liner; and, in a Democratic primary, singer Clay Aiken could be a runner-up once again.

Some GOP leaders are spending this primary season battling pesky insurgent challengers itching to take down the establishment. In Ohio, for instance, House Speaker John Boehner is trying to fend off a tea party opponent who’s best known for airing a sexually suggestive Web ad.

Jones is confronting perhaps the most serious political threat of his 19-year congressional career. Griffin has barnstormed the Outer Banks, casting Jones as a GOP squish and opponent of Israel who is all too frequently a thorn in the side of Republican leaders.

Griffin, 38, is getting plenty of help. He’s received an endorsement from former Alaska Gov. Sarah Palin, and outside groups such as the Ending Spending Action Fund have combined to plow in around $1 million to support him on TV. Wall Street honchos such as GOP megadonor Paul Singer, furious at Jones over his support for the Dodd-Frank financial reform bill, have sent Griffin contributions.

Jones, the son of a former congressman, has responded by casting Griffin as a Washington insider and carpetbagger who only recently moved back to North Carolina to run for the 3rd District seat.

No one thinks Boehner will lose his primary in which he faces a pair of obscure, tea party-aligned Republicans who’ve accused him of being an insider who’s forgotten about southwest Ohio.

But Boehner, who was first elected in 1990, has had to work harder than in recent primary seasons, airing TV ads for the first time in four years. Without any major statewide Republican primaries taking place in Ohio this year, the risk for Boehner is that his supporters won’t show up at the polls in their usual numbers.

The speaker has come under attack from the Tea Party Leadership Fund, a Washington-based political action committee that has spent more than $300,000 on ads attacking Boehner. The group is supporting J.D. Winteregg, a conservative activist who is best known for releasing a racy and viral Web commercial making fun of Boehner’s last name. (Winteregg lost his job as an adjunct professor at a Christian college because of the ad.)

Another Republican, computer consultant Eric Gurr, also is waging a long-shot bid to oust Boehner.

The Republican establishment is making a stand in the open-seat primary in North Carolina’s 7th District, with three Washington-based groups — the U.S. Chamber of Commerce, American Action Network and YG Network — combining to spend more than $400,000 on ads supporting David Rouzer, a former state senator.

Rouzer is trying to beat back Woody White, a conservative favorite and New Hanover County Commissioner who’s received the backing of former Arkansas Gov. Mike Huckabee. The groups backing Rouzer have hammered White over his career as a trial attorney.

White has hit back, casting Rouzer as a consummate insider who’s soft on immigration. The insurgent White has also put his opposition to President Barack Obama front and center, airing ads saying that he’ll fight the president’s “attacks on North Carolina.”

Rep. Mike McIntyre, a Blue Dog Democrat, is retiring from the 7th District seat after having narrowly defeated Rouzer in 2012. His departure hands Republicans one of their top pick-up opportunities in the country; whichever GOP candidate wins the primary in the conservative district will most likely skate in November.

American Idol contestant Clay Aiken drew plenty of buzz when he announced he’d be running for a North Carolina congressional seat as a Democrat. But he hasn’t gained much traction.

Through the middle of last month, Aiken had raised under $300,000, less than half of what his self-funding primary opponent, former state Commerce Secretary Keith Crisco, had taken in. And the singer has found himself on the receiving end of a brutal ad from Crisco that accused the entertainer of skipping meetings for a presidential committee on intellectual disabilities that he’d been appointed to.

Aiken, who’s taught special ed, responded by airing a radio commercial in which “American Idol” winner Ruben Studdard says the candidate has “dedicated his life to helping people with disabilities.”

The winner of the Democratic primary will face an uphill climb in the conservative 2nd District, which encompasses a swath of central North Carolina. Incumbent GOP Rep. Renee Ellmers has a primary of her own, with conservative radio show host Frank Roche attacking her for supporting immigration reform. Roche’s bid, however, is a tough one; he’s raised only about $20,000 — a fraction of the nearly $1 million Ellmers has taken in.

GOP Rep. David Joyce, who represents a swing northeastern Ohio district, might be one of the luckiest pols in the business.

After replacing former Republican Rep. Steve LaTourette on the ballot in 2012, Joyce easily defeated an obscure Democratic opponent. Heading into the current election season, it looked like the newcomer would be a prime target for Democrats. But national Democrats failed to recruit a strong candidate to run against him, having to settle on attorney Michael Wager, a relative unknown.

It turns out that Joyce won’t have much to worry about in the primary, either. Despite compiling a moderate record in the House, Joyce’s only major Republican opponent is state Rep. Matt Lynch, who’s raised just $90,000 — a small fraction of the more than $1.5 million that Joyce has brought in. And Joyce has received backup from the Chamber, which has spent around $300,000 on TV ads supporting him.